Field
The present disclosure relates to a photosensitive composition for a green color filter capable of enhancing light transmittance and improving contrast.
Discussion of the Background
Liquid crystal display (“LCD”) devices have been developed to have enlarged screens and high definition. Further, LCD devices have been adopted in various devices with an increasingly wide range of applications, from a monitor of a desktop computer to a monitor of a television. In accordance with the trends, there has been an increased need for a color filter used in an LCD or the like to have a high color purity. The requirement of the high color purity is particularly important to a high-definition display device which is designed to display an image of a high quality. Light passing through the color filters is configured to display a color of a corresponding pixel and the light of the colors are mixed together to form a color image. To this end, a color filter including pixels having significantly high color purity with predetermined three colors of RGB may be preferred.
Colorants used in the color filter need to have the following characteristics: desirable light-absorbing characteristics with regard to color reproduction; free from optical drawbacks such as light scattering which may lead to a contrast decrease in an LCD device and non-uniform optical concentration which may lead to a non-uniform color or rough color impression in a solid image sensor device; suitable resistance such as thermal-resistance, light-resistance, and moisture-resistance in accordance with a product usage environment; and a great molar extinction coefficient so as to achieve slimness.
Halogenated metal phthalocyanine dyes or halogenated metal phalocyanine pigments are commonly used to form a green pixel unit. More specifically, a dye or a pigment having a halogenated metal phthalocyanine structure in which eight or more halogen atoms are bonded to a benzene ring of a phthalocyanine molecule in each phthalocyanine molecule may be used as a green colorant constituting the green pixel unit of the color filter.
Among such dyes and pigments, pigment green 36 has been widely used despite having a low transmittance, and pigments are being developed to improve the low transmittance. In this regard, a C.I. pigment green 58, which is formed of polyhalogenated zinc phthalocyanine, has recently been developed as a pigment that may overcome the drawback, and is suggested as a pigment for a color filter.
Further, a scheme of using a dye, in lieu of a pigment, as a colorant has been suggested. However, a coloring curable composition including a dye needs to be added in large amounts when the dye has low molar extinction coefficient (ε). Accordingly, the amount of other components, such as a polymerization compound (monomer), a binder, or a photopolymerization initiator, in the coloring curable composition are necessarily reduced. As a result, curing properties, thermal-resistance after curing, and development properties of the composition may deteriorate.
Accordingly, there exists a need for a development of a dye improved in quality for being used in the manufacturing of the color filter of the LCD device.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the inventive concept, and, therefore, it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.